1. Field of the Invention
The present invention is directed to a method for lung therapy, and in particular to a method for lung therapy employing magnetic resonance (MR) imaging.
2. Description of the Prior Art
The pulmonary alveolae in healthy persons are maintained in shape by a film of surfactant, which is a complex mixtures of sphingolipids and proteins, so that the alveolae are uniformly filled with air when the person inhales. Under certain circumstances, for example, as a result of an infection, or immaturity of the lung, or circulatory damage, a degradation of this surfactant film occurs, and the pulmonary alveolae collapse and are no longer filled with fresh air. An exchange of O.sub.2 and CO.sub.2 then can no longer ensue between the inhaled air and the blood. This problem also frequently arises with premature babies, because premature babies have not yet built up enough surfactant. As a treatment for this phenomenon, a medication selected from various types of artificial surfactant preparations is administered to the patient in the respiratory path. This serves as a substitute for the surfactant which is present in a healthy person. In administering this surfactant, however, it is very difficult to select and maintain an appropriate dose.
The extent to which a lung has collapsed, and the spatial distribution of the collapsed portion of the lung, are not known before administering the medication therapy. After administration of the surfactant, it is uncertain where, within the lung, the administered surfactant has taken effect. Conventional imaging techniques do not supply information which adequately spatially resolved to allow such a determination to be made. An overdose of surfactant can lead to complications such as deficient aeration, due to the excess quantity of medication presenting a physical disturbance to breathing. An inadequate dose produces an insufficient effect to address the pathology. An optimum form of surfactant administration, such as administration in solvents, aerosol, etc., has not yet been found. Other more radical therapies, such as surgical removal of a passive portion of a lung, likewise require functional information so that healthy tissue is not excised.